What causes black smoke and stalling from a diesel engine?

Black smoke from a diesel engine typically indicates incomplete combustion, often due to an excess of fuel compared to the air available for combustion. This can be caused by issues such as a clogged air filter, malfunctioning fuel injectors, or a faulty turbocharger. Stalling may occur as a result of fuel delivery problems or air intake restrictions, leading to insufficient power generation. Regular maintenance and timely repairs are essential to prevent these issues.